MULTIPLEX COMMUNICATION SYSTEM

MULTIPLEX COMMUNICATION SYSTEM PRECAUTION 1 1. DISCONNECT AND RECONNECT CABLE OF NEGATIVE BATTERY TERMINAL NOTICE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected. System Name METER / GAUGE SYSTEM Cable (a) (c) See procedure See page ME-10 Before performing electronic work, disconnect the cable from the negative (-) battery terminal in order to prevent it from shorting and burning out. Before disconnecting and reconnecting the battery cable, turn the ignition switch OFF and the headlight dimmer switch OFF. Then loosen the terminal nut completely. Do not damage the cable or terminal. When the battery cable is disconnected, the clock and radio settings and stored DTCs are erased. Therefore, before disconnecting the battery cable, make a notes of them. Negative (-) Battery Terminal D033496E01

2 PARTS LOCATION MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM Main Body ECU (Driver Side J/B) B137551E01

3 SYSTEM DIAGRAM Main Body ECU BECU ECU-B POWER BDR Short Pin J/B ALT X2 X2 GND Battery B137552E01

4 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM SYSTEM DESCRIPTION 1. MULTIPLEX COMMUNICATION SYSTEM (BEAN) (a) The BEAN communication line consists of 2 systems: One is a system with a loop-shaped line that links the back door ECU with the main body ECU, which is located in the center of the line. Since the line for the back door ECU is loopshaped, communication can be maintained by the line that is not open even if part of the line becomes open for some reason. In the case that there is a short-circuit (bus-down) in the line, however, all the BEAN communication becomes impossible in the system and some DTCs are output. HINT: When bus-down occurs, communication from the related ECU stops. Therefore, DTCs cannot be output, so perform a DTC (SAE code) inspection using the intelligent tester. The back door ECU has a single communication line. Therefore, if the line has a short-circuit (busdown), the BEAN communication will be impossible and DTCs will not be output, either. 2. CHECK COMMUNICATION FUNCTION (a) Check the battery voltage. Standard voltage: 11 to 14 V Inspect the DTC output. (1) Check for DTCs concerning the main body ECU by connecting the intelligent tester to the DLC3 and turning the ignition switch ON. (2) When the display shows DTCs concerning the ECU being unconnected and the communication bus defective, perform the inspection depending on the troubleshooting procedures. HINT: When other DTCs are output, refer to the DTC table and check the applicable section.

5 HOW TO PROCEED WITH TROUBLESHOOTING HINT: Use this procedure to troubleshoot the multiplex communication system. The intelligent tester should be used in step 2. 1 VEHICLE BROUGHT TO WORKSHOP NEXT 2 CHECK FOR DTC (a) (c) Check for DTCs and note any codes that are output. Delete the DTC. Recheck for DTCs. Try to prompt the DTC by simulating the original activity that the DTC suggests. Result Result DTC does not recur DTC recurs Proceed to A B B GO TO DTC CHART A 3 OVERALL ANALYSIS AND TROUBLESHOOTING (a) Terminals of ECU (See page -6). NEXT 4 ADJUST, REPAIR OR REPLACE NEXT 5 CONFIRMATION TEST NEXT END

6 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM TERMINALS OF ECU 1. CHECK MAIN BODY ECU (a) Disconnect the 1B, 1E, 1F, 1L and E6 main body ECU connectors. Main Body ECU: Left View: E8 E7 E6 18 19 20 21 22 23 24 25 26 17 18 19 20 21 22 23 24 23 24 25 26 27 28 29 30 7 8 9 10 11 12 13 14 15 16 17 7 8 9 10 11 12 13 14 15 16 11 12 13 14 15 16 17 18 19 20 21 22 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 E8 E7 E6 Rear View: 1A 1B 10 9 8 7 20 19 18 17 6 5 4 3 2 1 16 15 14 13 12 11 1A 1B 5 4 13 12 11 10 9 3 8 2 7 1 6 1C 1D 1C 1D 2 1 1 2 6 5 4 3 1E 1E 1F 1F 12 11 24 23 10 9 22 21 8 7 20 19 6 5 4 3 2 1 18 17 16 15 14 13 8 7 16 15 6 5 4 3 2 1 14 13 12 11 10 9 B136051E02

7 Main Body ECU: Front View: 1H 1J 1G 2 1 4 3 17 18 19 20 21 22 1 2 3 4 5 6 23 24 25 26 7 8 9 10 27 28 29 30 31 32 11 12 13 14 15 16 4 3 2 1 1G 1H 1J 1K 1L 1K 1L 9 1011121314 1516 1 2 3 4 5 6 7 8 13 14 15 16 17 18 19 20 21 22 23 24 1 2 3 4 5 6 7 8 9 10 11 12 B136052E02

8 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM Standard voltage: Measure the voltage of the wire harness side connectors. Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition BECU (1B-4) - Body ground W-R - Body ground Power source (+B) Always 11 to 14 V BECU (1L-4) - Body ground W-R - Body ground Power source (+B) Always 11 to 14 V BECU (1F-12) - Body ground W-R - Body ground Power source (+B) Always 11 to 14 V BDR1 (1E-9) - Body ground B-Y - Body ground Power source (+B) Always 11 to 14 V X2 (E6-23) - Body ground BR-R - Body ground Multiplex communication signal During communication Signal waveform If the result is not as specified, there may be a malfunction on the wire harness side. 2. CHECK BACK DOOR ECU (a) Disconnect the S2 ECU connector. S5 S2 Standard voltage: Measure the voltage of the wire harness side connector. Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition GND (S2-3) - Body ground W-B - Body ground Ground for main power supply Ground for main power supply Below 1 V BECU (S2-5) - GND (S2-3) W-R - W-B Power source (+B) Always 11 to 14 V BDR (S2-4) - GND (S2-3) L-O - W-B Power source (+B) Always 11 to 14 V X2 (S2-1) - Body ground BR-R - Body ground Multiplex communication signal During communication Signal waveform SIG (S2-6) - Body ground B-R - Body ground Power source (IG) Ignition switch ON 11 to 14 V If the result is not as specified, there may be a malfunction on the wire harness side. B062706E01

9 DIAGNOSIS SYSTEM 1. DESCRIPTION (a) The main body ECU controls the functions of the multiplex communication system on the vehicle. Data of the multiplex communication system and the Diagnostic Trouble Codes (DTC) can be read through the Data Link Connector 3 (DLC3) of the vehicle. 2. CHECK DLC3 (a) The ECU uses ISO 15765-4 for communication. The terminal arrangement of the DLC3 complies with ISO 15031-3 and matches the ISO 15765-4 format. CG SG CANH SIL CANL BAT H100769E16 Symbols (Terminal No.) Terminal Description Condition Specified Condition SIL (7) - SG (5) Bus "+" line During transmission Pulse generation CG (4) - Body ground Chassis ground Always Below 1 Ω SG (5) - Body ground Signal ground Always Below 1 Ω BAT (16) - Body ground Battery positive Always 11 to 14 V CANH (6) - CANL (14) HIGH-level CAN bus line Ignition switch OFF* 54 to 69 Ω CANH (6) - CG (4) HIGH-level CAN bus line Ignition switch OFF* 200 Ω or more CANL (14) - CG (4) LOW-level CAN bus line Ignition switch OFF* 200 Ω or more CANH (6) - BAT (16) HIGH-level CAN bus line Ignition switch OFF* 6 kω or more CANL (14) - BAT (16) LOW-level CAN bus line Ignition switch OFF* 6 kω or more CAUTION: *: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector. Intelligent tester HINT: Connect the cable of the intelligent tester to the CAN VIM, connect the CAN VIM to the DLC3, turn the ignition switch ON and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle. DLC3 CAN VIM Intelligent Tester H102157E03

10 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM DLC3 CAN VIM Intelligent Tester H102157E03 If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual. 3. INSPECT BATTERY VOLTAGE Standard voltage: 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding. DTC CHECK / CLEAR 1. CHECK DTC (a) Connect the intelligent tester to the DLC3. Turn the ignition switch ON. (c) Enter the following menus: DIAGNOSIS/OBD/ MOBD/BODY/DTC INFO. (d) Check the DTCs on the tester screen. HINT: Refer to the intelligent tester operator's manual for further details. 2. CLEAR DTC (a) Connect the intelligent tester to the DLC3. Turn the ignition switch ON. (c) Erase the DTCs by following the prompts on the tester screen. (d) Enter the following menus: DIAGNOSIS/OBD/ MOBD/BODY/DTC INFO. HINT: Refer to the intelligent tester operator's manual for further details.

11 MULTIPLEX COMMUNICATION SYSTEM DIAGNOSTIC TROUBLE CODE CHART HINT: If a malfunction code is displayed during the DTC check, check the circuit corresponding to the code in the table below. Proceed to the page given for the circuit. DTC No. Detection Item Trouble area See page B1214 B1215 B1287 Short to B+ in Door System Communication Bus Malfunction Short to GND in Door System Communication Bus Malfunction Communication Stop 1. Back door ECU 2. Main Body ECU 3. Wire Harness 1. Back door ECU 2. Main Body ECU 3. Wire Harness 1. Back door ECU 2. Wire Harness -11-11 -14

12 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM DTC DTC B1214 B1215 Short to B+ in Door System Communication Bus Malfunction Short to GND in Door System Communication Bus Malfunction DESCRIPTION When a +B short circuit or body ground short circuit is detected on the communication bus (BEAN), BEAN is disabled and a DTC is output. DTC No. DTC Detection Condition Trouble Area B1214 B1215 Communication circuit and +B battery system short Door system communication circuit and body ground short Back door ECU Main body ECU Wire harness Back door ECU Main body ECU Wire harness WIRING DIAGRAM Main Body ECU X2 X2 B137556E01 INSPECTION PROCEDURE 1 CHECK DIAGNOSTIC TROUBLE CODE (BACK DOOR ECU) (a) Disconnect the back door ECU connector and check for DTCs B1214 and B1215.

13 Main Body ECU X2 X2 B137555E01 OK: Neither DTC B1214 nor DTC B1215 is output. NOTICE: Disconnect the connector in the operational sequence, and start the next step after the connector is reconnected. OK REPLACE BACK DOOR ECU NG 2 CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BACK DOOR ECU) (a) Check for a short-circuit in B+ or body ground. Main Body ECU X2 X2 B137554E01

14 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM Wire Harness Side: Main Body ECU E6 Disconnect the S2 back door ECU connector and E6 main body ECU connector. (1) Measure the voltage between the terminals of the S2 back door ECU or E6 main body ECU connector and body ground. X2 1 10 2 3 4 5 6 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Front View S2 X2 1 2 4 5 6 7 3 8 Front View B137571E03 Standard voltage Tester Connection Condition Specified Condition E6-23 (X2) or S2-1 (X2) - Body ground Ignition switch ON Below 1 V Standard resistance (2) Check the resistance. Tester Connection Specified Condition E6-23 (X2) or S2-1 (X2) - Body ground 10 kω or higher (c) Reconnect the back door ECU connector and main body ECU connector. NG REPAIR OR REPLACE WIRE HARNESS BETWEEN MAIN BODY ECU AND BACK DOOR ECU OK REPLACE MAIN BODY ECU

15 DTC B1287 Communication Stop DESCRIPTION DTC B1287 is output when communication between the back door ECU and the main body ECU stops for more than 10 seconds. DTC No. DTC Detection Condition Trouble Area B1287 Back door ECU communication stops Back door ECU Wire harness WIRING DIAGRAM Main Body ECU BECU ECU-B POWER BDR Short Pin J/B ALT X2 X2 GND Battery B137552E01

16 MULTIPLEX COMMUNICATION MULTIPLEX COMMUNICATION SYSTEM INSPECTION PROCEDURE 1 CHECK COMMUNICATION LINE Wire Harness Side: Main Body ECU E6 (a) (c) Disconnect the E6 main body ECU and S2 back door ECU connectors. Check the resistance. Standard resistance Tester Connection Specified Condition E6-23 (X2) - S2-1 (X2) Below 1 Ω Reconnect the main body ECU and back door ECU connectors. X2 1 10 2 3 4 5 6 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Front View NG REPAIR OR REPLACE HARNESS OR CONNECTOR S2 X2 1 2 4 5 6 7 3 8 Front View B137571E03 OK 2 CHECK BACK DOOR ECU (POWER SOURCE) Wire Harness Side: (a) Disconnect the S2 back door ECU connector. Measure the voltage between the terminals of the S2 back door ECU connector and body ground. Standard voltage Tester Connection Specified Condition S2-5 (BECU) - Body ground 11 to 14 V S2 1 2 3 4 5 6 7 8 BECU Front View (c) NG Reconnect the ECU connector. REPAIR OR REPLACE HARNESS OR CONNECTOR B137572E01

17 OK 3 CHECK BACK DOOR ECU (GROUND) Wire Harness Side: (a) (c) Disconnect the S2 back door ECU connector. Check the resistance. Standard resistance Tester Connection Specified Condition S2-3 (GND) - Body ground Below 1 Ω Reconnect the ECU connector. S2 1 2 4 5 6 7 3 8 GND NG REPAIR OR REPLACE HARNESS OR CONNECTOR Front View B137572E05 OK REPLACE BACK DOOR ECU